For purposes of communicating well fluid to a surface of a well, such as an oil or gas well, a well may include production tubing. Often times, to enhance the rate at which fluid is produced through the production tubing, an artificial-lift technique is employed. One such technique involves injecting gas into the production tubing to displace some of the well fluid in the tubing with lighter gas. The displacement of the well fluid with the lighter gas reduces the hydrostatic pressure inside the production tubing and allows reservoir fluids to enter the wellbore at a higher flow rate. The gas to be injected into the production tubing typically is conveyed down hole via an annulus and enters the production tubing through one or more gas lift barrier valves.
The gas lift barrier valves may be in side pocket gas lift mandrels. These mandrels control the communication of gas between the annulus and a central passageway of the production tubing. Each of these gas lift mandrels can have one or more associated gas lift barrier valves for purposes of establishing one way fluid communication from the annulus to the central passageway.
In the past, gas lift barrier assemblies have been prone to leakage. Leakage has previously been measured using permanent gauges, which measure temperature and or pressure and are connected with the mandrel. In an effort to alleviate leakage, a dual-barrier side pocket mandrel, such as the one described in U.S. Patent Appl. Pub. No. 20110315401 has been used. However, this mandrel does not allow temperatures and/or pressures in the gas lift system to be measured in real time through the use of permanent sensors. Thus, in an effort to optimize a gas lift system, there exists a continuing need to both prevent leakage and accurately determine if leakage is occurring through the use of pressure/temperature sensors.